Significant enhancement of nitrogen photofixation to ammonia and hydrogen storage by a MIL-53 (Fe) based novel plasmonic nanocatalysis at ambient condition

Since hydrogen (H₂) plays a vital role in industry, its storage is crucial. Typically, H₂ is produced through water-splitting and then stored as ammonia. This process is very time-consuming and costly. Plasmonic metal nanocatalysts, including copper (Cu), silver (Ag), and gold (Au), are promising new ways to stimulate photocatalytic reactions. In this study, Ag/AgCl and Pd plasmonic NPs on the MIL-53 (Fe) by solvothermal method for Nitrogen (N₂) photofixation to ammonia (NH₃) with high efficiency under ambient conditions. Famous techniques such as FT-IR, XRD, BET, SEM, EDX/Map TEM, and TGA/DSC have been used to determine and confirm physicochemical surface variation while preparing and modifying the MIL-53 (Fe)@Ag/AgCl and MIL-53 (Fe)@Pd0 nanocatalysts. The synthesized plasmonic nanocatalysts display better photocatalytic activities during N₂ photofixation, with a maximum NH₃ production rate of 183.547 µmol·h^{- 1}·g^{- 1} (MIL-53 (Fe)@Ag/AgCl(20%)) and 106.746 µmol·h^{- 1}·g^{- 1} (MIL-53 (Fe)@Pd0(2%)) under visible light irradiation. This issue was attributed to the ability of Ag and Pd plasmonic NPs to harvest light to produce abundant hot electrons and Fe NPs to create active sites for N₂ adsorption and activation. The MIL-53 (Fe)@Ag/AgCl(20%) and MIL-53 (Fe)@Pd0(2%) plasmonic compared to MIL-53 (Fe), have increased by 20-fold and 12-fold, respectively. This work of MOF-based plasmonic nanocatalysts for the N₂ to NH₃ photofixation will provide insight into the rational design of catalysts with high efficiency at ambient conditions.